Zenith LAA Occlusion System

This study is evaluating a device called the Zenith LAA Occlusion System, which is a small implant inserted into the left atrial appendage (a small pouch in the heart) to reduce stroke risk in people with non-valvular atrial fibrillation (an irregular heartbeat). This procedure offers an alternative to long-term blood thinner medications. **You may be eligible if...** - You are 18 or older with a confirmed diagnosis of atrial fibrillation not caused by a heart valve problem - Your doctor has determined that you need the left atrial appendage to be sealed - You are willing to attend follow-up visits as required **You may NOT be eligible if...** - You have had a heart attack, stroke, or TIA in the past 90 days - You have severe heart failure symptoms (Class III or IV) - You have a bleeding disorder or very low platelets - You have severe kidney disease or are on dialysis - You need long-term blood thinners for a condition other than atrial fibrillation - You have an active infection or active pericarditis - You are pregnant or planning to become pregnant within 12 months - You have a BMI over 40 or a life expectancy of less than 1 year Talk to your doctor to see if this trial is right for you.